Immunohistochemical staining of LRP in the ischemic brain 3 hours after middle cerebral artery occlusion. Animals were subjected to MCAO followed by continuous MRI monitoring of cerebral blood flow (CBF), apparent diffusion coefficient (ADC) of water, and tissue changes associated with cerebral edema (T2-weighted images), followed by immunohistochemical analysis of LRP expression 180 minutes after the onset of the ischemic insult. (A-B) Changes in CBF (A) and ADC of water (B) 30 minutes after MCAO. Arrows in panel A depict the area of the brain with a greater than 80% decrease in CBF (dark zone). Arrows in panel B denote the area of irreversibly injured brain (dark area). (C) T2-weighted image of the same brain of panels A and B. Arrows depict the edge of the ischemic tissue with evolving cerebral edema (hyperintense signal). The black squares represent the areas of the brain were the immunohistochemical staining for LRP expression was performed. (D-I) Immunohistochemical staining with an antibody against CD31 (PECAM-1) (D,G) and the R2629 LRP antibody (E,H) in the area corresponding to the black squares in the ischemic (D-F) and nonischemic (G-I) hemispheres. Panels F and I correspond to merged images. (J-O) Immunohistochemical staining with an antibody against von Willebrand factor (J,M) and the 11H4 LRP antibody (K,N) in the area corresponding to the black squares depicted in panel C in the ischemic (J-L) and nonischemic (M-O) hemispheres. Panels L and O correspond to merged images. Images were visualized using a Leica DMRBE microscope (Leica, Houston, TX) equipped with a 100×/1.30 numerical aperture (NA) oil objective lens and a Leica DC 500 camera. Images were processed using software provided by the camera manufacturer.
